Left atrial dysfunction in bicuspid aortic valve patients with severe aortic stenosis is associated with postoperative atrial fibrillation following aortic valve replacement

Abstract Aims To investigate (i) the association between preoperative left atrial (LA) reservoir strain and postoperative atrial fibrillation (AF), and (ii) the incidence of postoperative ischemic stroke events separately in bicuspid (BAV) and tricuspid aortic valve (TAV) patients after surgical aortic valve replacement for isolated severe aortic stenosis (AS). Methods and results We prospectively enrolled 227 patients (n = 133 BAV and n = 94 TAV) with isolated severe AS scheduled for aortic valve replacement. A comprehensive intra- and interobserver validated preoperative echocardiogram with analysis of LA reservoir strain was performed. Postoperative AF was defined as a sustained (>30 s) episode of atrial fibrillation or atrial flutter. Timing of neurological events were defined in accordance with the Valve Academic Research Consortium (VARC)-3 criteria for stroke. Postoperative AF occurred in 114 of 227 patients (50.2%), with no difference between BAV and TAV patients (48.1% vs. 53.1%, P = 0.452). Persisting postoperative AF at discharge was more frequent in BAV patients (29.7% vs. 8.0%, P = 0.005). Preoperative LA reservoir strain was independently associated with postoperative AF (odds ratio [OR] = 1.064, 95% CI 1.032–1.095, P < 0.001), with a significant interaction between LA reservoir strain and aortic valve morphology (Pinteraction = 0.002). The cumulative TIA/stroke incidence during follow-up was significantly higher in BAV patients (19.1% vs. 5.8% at five years). Conclusion Preoperative LA function was associated with postoperative AF after aortic valve replacement in BAV AS patients, while postoperative AF in TAV AS patients likely depends on transient postoperative alterations and traditional cardiovascular risk factors. TIA/stroke during follow-up was more common in BAV AS patients.